This invention relates to dynamoelectric machines which have stator members with multi-looped coils disposed therein constituting stator windings, and more particularly to a combined electrical and coolant distribution system for the stator windings.
In the past, separate distribution systems have been used for supplying coolant to the stator windings and obtaining electricity from the same. The coolant supply system frequently consisted of circular manifolds in fluid communication with the stator windings in an electrically insulated manner with one manifold being located at each axial end of the stator windings while the electrical distribution system consisted of parallel, arcuate connector rings which were electrically connected at one end to the terminating portions of the stator windings and at their other end provided phase lead extensions. Previous systems thus had the following adverse consequences: (1) a separate cooling circuit for the phase connections was required; (2) coolant manifold components were arranged to fit into a connection zone of the stator windings when that zone was already crowded by the presence of phase connections; (3) accessibility for maintenance on the parallel, arcuate rings, stator coil supports, and core end portions was very limited; (4) limitations on the methods and equipment for over-potential testing of the stator windings were imposed; and (5) the use of special parts for the distribution of coolant to the end turns such as long hose connections capable of withstanding all voltages from stator winding potential to ground for all intended operating and testing conditions were required.
U.S. Pat. No. 3,112,415 by Bahn et al. utilizes the arcuate rings and phase leads as a coolant conduit, but retains a separate coolant inlet manifold with the accompanying disadvantages which are inherent in its use. U.S. Pat. Nos. 3,634,705 by Fidei and 3,614,493 by Collings also teach hydraulic and electric connecting means for the stator windings, but neither uses the arcuate connection rings for both functions or eliminates the coolant supply manifold.
Superconducting generators and other dynamoelectric machines which use air gap stator windings have the potential for generating power at considerably higher voltage levels than has been the practice with generators of more conventional design. Such windings must be supported and braced to withstand relatively higher force levels than presently exist for windings contained in conventional stator slots. Air gap stator windings used in superconducting generators (e.g., with superconducting rotor field windings) can have higher voltage levels which will be accompanied by more individual coil connections for each stator winding than now exist. The problem of making coolant connections from coolant manifolds at ground potential, which is a common present practice, through hoses which are long enough to provide sufficient electrical insulation to withstand the higher voltage levels and numerous enough for the increased number of coils in each winding will be a very formidable one.